Orientational Wetting in Hybrid Liquid Crystalline Block Copolymers

Wong, Gcl; Commandeur, J. M.; Fischer, H.; Jeu, de Wh Wim

doi:10.1103/physrevlett.77.5221

Cited by 52 publications

(57 citation statements)

References 27 publications

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“…Consequently, crystallizable block copolymers in thin films or at surfaces present interesting systems for the creation of patterned substrates exhibiting multiple length scales. Amorphous block copolymer systems encounter difficulties if one intends to use them for patterning substrates on the nanometer scale [74,[77][78][79][80][81][82][83][84][85][86][87], in particular regarding the ordering effect over large distances and the ability to produce long-range order.…”

Section: Formation Of Aligned Surface Patternsmentioning

confidence: 99%

Morphologies of diblock copolymer thin films before and after crystallization

et al. 2000

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Spin-coated thin films of about 100 nm of low-molecular-weight hydrogenated poly(butadiene-bethyleneoxide) (PB h -PEO) diblock copolymers have been crystallized at various constant temperatures. Crystallization has been observed in real time by light microscopy. Detailed structural information was obtained by atomic force microscopy, mainly enabled by the large viscoelastic contrast between amorphous and crystalline regions. The behavior in thin films is compared to the bulk properties of the polymer. Crystallization started from an annealed microphase separated melt where optical microscopy indicated a lamellar orientation parallel to the substrate. A small difference in the length of the crystallizable block produced significantly different crystallization behavior, both in the bulk and in thin films. For thin films of the shortest diblock copolymer (45% PEO content) and for an undercooling larger than about 10 degrees, crystallization created vertically oriented lamellae. These vertical lamellae could be preferentially aligned over several micrometers when crystallization occurred close to a three-phase contact line. Annealing at temperatures closer to the melting point or keeping the sample at room temperature for several months allowed the formation of a lamellar structure parallel to the substrate. A tentative interpretation based on kinetically caused chain folding and relaxation within the crystalline state, with implications on general aspects of polymer crystallization, is presented.PACS. 61.41.+e Polymers, elastomers, and plastics -68.55.-a Thin film structure and morphology -68.60.Dv Thermal stability, thermal effects

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Section: Formation Of Aligned Surface Patternsmentioning

confidence: 99%

Morphologies of diblock copolymer thin films before and after crystallization

et al. 2000

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“…Ultrathin LB fi lms of P(VDF-TrFE) copoly-mers are initially continuous and fl at [8], but annealing in the paraelectric phase results in the spontaneous appearance of isolated ferroelectric nanomesas approximately 9 nm thick by 100 nm in diameter, with the polymer chains lying parallel to the substrate [3]. The uniform shape and fl at top of the nanomesas imply that their formation involves a surface reorganization process [4,9,10], a kind of crystalline plastic fl ow [6,7], rather than liquid fl ow associated with melted or glassy materials. The nanomesas have the same (110) crystal orientation [3] as the continuous LB fi lms [5], which means the polymer chains remain in plane.…”

Section: Introductionmentioning

confidence: 99%

Effects of annealing conditions on ferroelectric nanomesa self-assembly

Bai¹,

Poulsen

Ducharme

2006

J. Phys.: Condens. Matter

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We report the results of studies of the effects of annealing conditions on the morphology of ferroelectric nanomesas. The nanomesa patterns were fabricated by self-assembly from continuous ultra-thin Langmuir-Blodgett fi lms of copolymers of vinylidene fl uoride and trifl uoroethylene. Annealing in the paraelectric phase induced surface reorganization into disc-shaped ferroelectric nanomesas approximately 9 nm thick and 100 nm in diameter. Several factors affect the nanomesa dimensions, such as polymer composition, substrate material, deposition conditions, and annealing temperature. The height and diameter of the nanomesas both increase with increasing annealing temperature. Annealing studies in the ferroelectric-paraelectric coexistence region show that only the paraelectric phase is mobile. From this we conclude that the paraelectric phase supports a kind of plastic crystalline fl ow connected with dynamic disorder of the polymer conformation.

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“…This possibility has been exploited to orient a lamellar phase of a hybrid smectic LC/amorphous block copolymer perpendicularly onto a homogeneous float glass substrate. [8] In this report we show that lamellae-like surface ripples on a nanometer scale can be induced in LC polyacrylate films on a homogeneous substrate. The film surface shows regular height modulations with a periodicity of 9 nm, which are attributed to a coupling between local LC order and surface curvature energy.…”

mentioning

confidence: 97%

Microscopic Surface Patterns of a Liquid Crystalline Polyacrylate Film

2001

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Lamellae‐like surface ripples, as shown in the Figure, can be induced on liquid crystalline polyacrylate films. The film surface shows regular height modulations, which are attributed to coupling between local liquid crystal ordering and surface curvature energy. The properties of these films, including their use for the patterning of otherwise homogeneous surfaces, are discussed in this communication.

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Orientational Wetting in Hybrid Liquid Crystalline Block Copolymers

Cited by 52 publications

References 27 publications

Morphologies of diblock copolymer thin films before and after crystallization

Morphologies of diblock copolymer thin films before and after crystallization

Effects of annealing conditions on ferroelectric nanomesa self-assembly

Microscopic Surface Patterns of a Liquid Crystalline Polyacrylate Film

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